PURPOSE: Simple changes to bonding technique can improve resin-dentin bond strengths. The objective of this study was to evaluate the effects of multiple coatings of two all-in-one adhesive resins on both microtensile bond strength (microTBS) and nanoleakage. MATERIALS AND METHODS: The mid-coronal occlusal dentin of extracted human molars was used. Two all-in-one adhesives--iBond (Heraeus Kulzer) and Xeno III (Caulk Dentsply)--were applied to 320-grit abraded dentin surfaces. In groups 1 and 3 during bonding, monomer application and solvent evaporation were done 1, 2, 3, 4 or 5 times on the dentin surface before light curing. In groups 2 and 4 after light curing the first layer, the adhesive was re-applied, the solvent evaporated, and the layer light cured. This was repeated from 2 to 5 times, followed by creation of composite buildups. After 24 h storage in 37 degrees C water, the teeth were sectioned perpendicular to the adhesive interface to produce multiple beams of composite-bonded dentin, approximately 0.9 mm2 in area. These were tested to failure in tension. Data were evaluated by three-way ANOVA (material vs coatings vs light curing) followed by multiple comparisons at alpha = 0.05. Additionally, nanoleakage of silver uptake and adhesive layer thickness were evaluated using transmission electron microscopy (TEM). RESULTS: The results indicated that bond strengths increased with the number of coatings (p < 0.0001) with both adhesives, up to 3 layers, especially if each layer was light cured. Nanoleakage of silver tended to decrease with each coat in both adhesive systems. CONCLUSION: By simply applying more coats of adhesive, the strength and quality of dentin adhesion can be improved.
PURPOSE: Simple changes to bonding technique can improve resin-dentin bond strengths. The objective of this study was to evaluate the effects of multiple coatings of two all-in-one adhesive resins on both microtensile bond strength (microTBS) and nanoleakage. MATERIALS AND METHODS: The mid-coronal occlusal dentin of extracted human molars was used. Two all-in-one adhesives--iBond (Heraeus Kulzer) and Xeno III (Caulk Dentsply)--were applied to 320-grit abraded dentin surfaces. In groups 1 and 3 during bonding, monomer application and solvent evaporation were done 1, 2, 3, 4 or 5 times on the dentin surface before light curing. In groups 2 and 4 after light curing the first layer, the adhesive was re-applied, the solvent evaporated, and the layer light cured. This was repeated from 2 to 5 times, followed by creation of composite buildups. After 24 h storage in 37 degrees C water, the teeth were sectioned perpendicular to the adhesive interface to produce multiple beams of composite-bonded dentin, approximately 0.9 mm2 in area. These were tested to failure in tension. Data were evaluated by three-way ANOVA (material vs coatings vs light curing) followed by multiple comparisons at alpha = 0.05. Additionally, nanoleakage of silver uptake and adhesive layer thickness were evaluated using transmission electron microscopy (TEM). RESULTS: The results indicated that bond strengths increased with the number of coatings (p < 0.0001) with both adhesives, up to 3 layers, especially if each layer was light cured. Nanoleakage of silver tended to decrease with each coat in both adhesive systems. CONCLUSION: By simply applying more coats of adhesive, the strength and quality of dentin adhesion can be improved.
Authors: Milena Cadenaro; Lorenzo Breschi; Frederick A Rueggeberg; Kelli Agee; Roberto Di Lenarda; Marcela Carrilho; Franklin R Tay; David H Pashley Journal: Dent Mater Date: 2008-06-20 Impact factor: 5.304